The detection is done in a continuous flow microfluidic device with confocal microscopy. In order to carry out the spatial recognition of the fluorescent tags along the length of the DNA fragment, it needs to be stretched out into a linear form using a funnel. High molecule throughput is important as the detection confidence of this technology relies on observing as many tags as possible in the specified experimental period.
The team looks at the relationship between the funnel taper shape and related parameters, such as fluid velocity and fragment length, to improve the current designs and increase throughput. Their new geometries are able to keep the tension applied to the DNA constant during the detection process. Because DNA fragments come in various lengths, a very important goal is to maximise the range of lengths that can be stretched effectively with the funnel. The influence of channel etch depth on fluid flow, and therefore throughput, is also considered.
